Answer:
b. Hydrofluoric acid/sodium fluoride (pKa=3.14).
Explanation:
Hello!
In this case, since the buffer capacity is related to how good a buffer behaves under the addition of acidic or basic substances in the light of holding the pH as constant as possible, we need to keep in mind that the best buffer must have a pKa as close as possible to the desired pH, that is, if the desired pH here is 3.20, we must pick the acid/base pair which the pKa cosest to 3.20.
In such a way, since b. Hydrofluoric acid/sodium fluoride (pKa=3.14 ) and c. Nitrous acid/sodium nitrite (pKa=3.34) have a pKa close to 3.20, the closest one is b. Hydrofluoric acid/sodium fluoride pKa=3.14 which is 0.06 pH units away from the desired pH, therefore the answer is b. Hydrofluoric acid/sodium fluoride pKa=3.14.
Best regards!
Which type of energy would digesting
food be?
A. Feild
B.solar
C. Thermal
D. kinetic
E. Tube
F. chemical
Answer:
F . chemical
Explanation:
Answer:
f
Explanation:
The maximum allowable concentration
of lead in drinking water is 9.0 ppb. If 2.0
X 10 grams of lead is present in 250
mL of water, is it safe to drink the water?
Support your answer with mathematical
proof.
We are given:
Maximum concentration of Lead in water = 9 ppb
Mass of Lead in the given solution = 20 grams
Volume of water in the given solution = 250 mL
What is 1 ppb?
1 ppb, short for parts-per-billion. As from its name itself, ppb is used to find how many molecules of solute are present per 1 Billion molecules of the solvent
you can also use it in grams to get the formula:
1 ppb = 1 gram of solute / 1 Billion grams of Solvent
Finding the Ideal ppb concentration:
We are given that the maximum allowed concentration is 9 ppb
which means that we need 9 grams of the solute per 1 Billion grams of Solvent: 9 grams of Solute / 10⁹ grams of Solvent
ppb Concentration of the given solution:
We have 20 grams of Solute in 250 mL of water
Since the density of water is 1 gram/mL
20 grams of Solute / 250 grams of Solvent
As we can see, this fraction is FAR more large that the maximum ppb concentration
This means that the concentration of Lead in the Given solution is higher than the maximum amount and Hence, is unfit to drink
What is the molarity of a CsOH solution if 30.0 mL of the solution requires exactly 26.4 mL of 0.25 M HBr solution to neutralize it?
Answer: 8.89M
Explanation:
draw a well-labelled diagram showing how your body digests food
i too used it
i thought it will help
nice time. .....
Explanation:
...................
A wave is moving toward the shore If its frequency is 2.7 hertz, what is its wavelength? What would the correct number of significant figures be?
Answer:
λ = 1.1×10⁸ m
Explanation:
Given data:
Frequency of wave = 2.7 Hz
Wavelength of wave = ?
Solution:
Formula:
Speed of wave = frequency × wavelength
Speed of wave = 3×10⁸ m/s
now we will put the values in formula.
3×10⁸ m/s = 2.7 s⁻¹ × λ
λ = 3×10⁸ m/s /2.7 s⁻¹
λ = 1.1×10⁸ m
Which TWO statements describe the ocean floor giving brainliest plz help and explain
Answer:
A.There are many active undersea volcanoes
B.There are long underwater mountain chains
1.50 x 10^23 atoms Mg
plz help it's due in 5 min
Answer:
what is the question then we can help you out
Answer:
51.84
Explanation:
Chose the molecular formula that represents an organic molecule.
(A)C6H12O6
(B)NH2
(C)Cu2O
(D)H2O
234 92U undergoes alpha decay. What is the atomic number of the resulting element. Express your answer numerically as an integer.
Answer:
90
Explanation:
Let ʸₓA be the resulting element when ²³⁴₉₂U under goes alpha decay.
Thus, the equation is given below
²³⁴₉₂U —> ʸₓA + ⁴₂He
The atomic number x of the resulting element can be obtained as follow:
92 = x + 2
Collect like terms
92 – 2 = x
90 = x
Therefore,
x = 90
Thus, the atomic number of resulting element is 90.
How is coffee, Lemonade, Soda, Vinegar, Orange Juice an acid?
What is the number of
nitrogen atoms in 12.0 g of
CO(NH2)?
[Avogadro constant = 6.02
x 1023 moll; Molar mass of
CO(NH2) = 60 g mol']
Answer:
1.2 x 10²³atoms
Explanation:
Given parameters:
Mass of CO(NH₂) = 12g
Unknown:
Number of Nitrogen atoms = ?
Solution:
Given compound;
CO(NH₂);
In;
1 mole of CO(NH₂), we have 1 mole of N
let us find the number of moles of CO(NH₂);
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Number of moles = [tex]\frac{12}{60}[/tex] = 0.2moles
Since
1 mole of CO(NH₂), we have 1 mole of N
0.2 mole of CO(NH₂) will have 0.2mole of N
1 mole of a substance contains 6.02 x 10²³ atoms
0.2 mole of N will contain 0.2 x 6.02 x 10²³ atoms = 1.2 x 10²³atoms
Why is Nertic zone particularly rich in living things?
Answer:
It is rich in organisms because sunlight passes through its shallow water enabling photosynthesis to occur.
Explanation:
I hope that helped!!
About how many times more massive is a neon atom than a helium atom?
Answer:
neon is about five times more massive than helium.
Explanation:
got this one right lol
What will the pressure of the gas be if the temperature rises to 87°C?
A. 60 kPa
B. 161 kPa
C. 16 kPa
D. 41 kPa
Answer:
A. 60 kPa
Explanation:
P2 = p1 times t2 / t1
can you help me plz..?!!
Answer:you killed a person
Explanation:that is a example
I looked around just put these into your own words :)
Explanation:
One common method of separation is filtration. Filters are used everywhere. We use them in our houses to filter dust and mites out of the air we breathe. We use them to filter impurities from our water.
It is important to be able to separate mixtures to obtain a desired component from the mixture and to be able to better understand how each component works.
In chemistry and chemical engineering, a separation process is commonly used to transform a mixture of substances into two or more distinct materials. The separated products might differ in chemical properties or some physical property, such as size or crystal modification or other separation into different components.
Hopefully this helps you out.
A 30.00 mL sample of vinegar is titrated with 0.4190 M NaOH(aq). If the titration requires 27.83 mL of NaOH(aq), what is the concentration of acetic acid in the vinegar?
Answer:
0.389 M
Explanation:
Using the formula; CaVa = CbVb
Where;
Ca = concentration of acid
Cb = concentration of base
Va = volume of acid
Vb = volume of base
Based on the provided information in the question, Va = 30mL, Ca=?, Vb = 27.83mL, Cb = 0.4190 M
Hence, CaVa = CbVb
Ca = CbVb/Va
Ca = 0.4190 × 27.83 ÷ 30
Ca = 11.6607 ÷ 30
Ca = 0.3886
Ca = 0.389 M
Therefore, the concentration of acetic acid in the vinegar is 0.389 M
Draw a structural formula for the ketal formed when two molecules of ethanol combine with one cyclohexanone molecule.
Answer:
Explanation:
The nucleophilic addition reaction of alcohol to a carbonyl compound in an acidic medium forms a hemiketal in the case of a ketone or a hemiacetal in the case of an aldehyde. When the carbonyl function is brought into contact with two alcohol functions, a ketal (for a ketone) or an acetal (for an aldehyde) is obtained.
From the image attached below, we will see how ketal formation occurs by the reaction of two molecules of ethanol with one cyclohexanone molecule.
What are the products in a chemical reaction?
A. The substances that result from a chemical reaction
B. The substances that do not take part in a reaction
c. The substances that cause the reaction to occur
thing
D. The substances that react in a chemical reaction
Answer:
A
Explanation:
The product is the result of the chemical reaction hope that helped
HELP Which type of light is stored energy?
A. Kinetic
B. Potential
C. Thermal
D. Field
Answer:
B
Explanation:
Answer:
Potential
Explanation:
Match the molecules to the correct state of matter
Answer:
1. solid, 2.liquid, 3.gas.
Answer:
1 b. solid
2 a. liquid
3 c. gas
What is the volume of 139.05 g of neon gas at STP?
Ans:___L Ne
Given :
Mass of neon gas at STP.
To Find :
The volume of 139.05 g of neon gas at STP.
Solution :
Molar mass of neon, M = 20 g.
Number of moles in 139.05 g of neon :
n = 139.05/20 ≈ 7 moles
We know, volume of 1 mole of any atom/molecules in STP is 22.4 L of volume.
So, volume of 7 moles of neon is :
V = 7×22.4 L
V = 156.8 L
Therefore, volume of 139.05 g of neon gas at STP is 156.8 L.
Which functional group will cause a compound to have a boiling point greater than that predicted only by molar mass?
-Alkene
-alkane
-ketone
-ether
-alcohol
Answer: Alcohol
Explanation:
During electrolysis, where do reduction reactions occur?
Answer:
at the negative cathode
Explanation:
Reduction happens at the negative cathode because this is where positive ions gain electrons. Oxidation happens at the positive anode because this is where negative ions lose electrons.
Answer:
B. in the cathode of an electrolytic cell
Explanation:
What is the independent variable and the dependent variable?
Answer: A variable that is intentionally changed during an experiment
Explanation:Hope it works
True or False: A buffer solution containing equimolar amounts of the base, aniline, and the salt of its conjugate acid, aniline hydrochloride, will result in an acidic buffer solution. (aniline: Kb = 4.3x10-10)?
Answer:
It is TRUE!
Explanation:
Answer:
True is your answer
Explanation:
About how far does the S wave travel through Earth in 13 minutes? 2,000 km 4,000 km 6,000 km 8,000 km
Answer:
It travel's about 4,000 km through the Earth in 13 minutes.
Answer:
4,000 km is the correct answer!!!
An atom of an element can be identified from its
A. atomic mass
B. number of neutrons
C. Total change
D. Number of protons
Answer:
D. number of protons
Explanation:
Sana makatulong
Suppose you have 250.0 mL of a 0.350 M sodium hydroxide solution. How many moles of sodium hydroxide are in the solution?
Explanation:
number of moles can be derived from molarity law as shown in the figure
The number of moles of sodium hydroxide are in the solution should be considered as the 0.0875 moles.
Calculation of the number of moles:
Since there is 50.0 mL of a 0.350 M sodium hydroxide solution.
So here the no of moles should be
[tex]= Molarity * volume\\\\= 250 *10^-3 * 0.350[/tex]
= 0.0875 moles
hence, The number of moles of sodium hydroxide are in the solution should be considered as the 0.0875 moles.
Learn more about moles here: https://brainly.com/question/8759992
Write the balanced Ka and Kb reactions for HSO3- in water. Be sure to include the physical states of each species involved in the reaction.Ka:_________Kb:_________NOTE: Use the chemical equation editor tool to input the physical states. Do not subscript the physical states of the compounds.
Answer:
Ka = [H₃O⁺] [SO₃²⁻] / [HSO₃⁻]
Kb = [OH⁻] [H₂SO₃] / [HSO₃⁻]
Explanation:
An amphoteric substance as HSO₃⁻ is a substance that act as either an acid or a base. When acid:
HSO₃⁻(aq) + H₂O(l) ⇄ H₃O⁺(aq) + SO₃²⁻(aq)
And Ka, the acid dissociation constant is:
Ka = [H₃O⁺] [SO₃²⁻] / [HSO₃⁻]When base:
HSO₃⁻(aq) + H₂O(l) ⇄ OH⁻(aq) + H₂SO₃(aq)
And kb, base dissociation constant is:
Kb = [OH⁻] [H₂SO₃] / [HSO₃⁻]